Wikipedia Search Force Article Talk Language Download PDF Watch Edit For other uses, see Force (disambiguation). "Physical force" redirects here. For other uses, see Physical force (disambiguation). In physics, a force is an influence that can cause an object to change its velocity, i.e., to accelerate, meaning a change in speed or direction, unless counterbalanced by other forces. The concept of force makes the everyday notion of pushing or pulling mathematically precise. Because the magnitude and direction of a force are both important, force is a vector quantity. The SI unit of force is the newton (N), and force is often represented by the symbol F. Force Forces can be described as a push or pull on an object. They can be due to phenomena such as gravity, magnetism, or anything that might cause a mass to accelerate. Common symbols � → {\displaystyle {\vec {F}}}, F, F SI unit newton (N) Other units dyne, pound-force, poundal, kip, kilopond In SI base units kg·m·s−2 Derivations from other quantities F = ma Dimension � � � − 2 {\displaystyle {\mathsf {M}}{\mathsf {L}}{\mathsf {T}}^{-2}} Force plays a central role in classical mechanics, figuring in all three of Newton's laws of motion, which specify that the force on an object with an unchanging mass is equal to the product of the object's mass and the acceleration that it undergoes. Types of forces often encountered in classical mechanics include elastic, frictional, contact or "normal" forces, and gravitational. The rotational version of force is torque, which produces changes in the rotational speed of an object. In an extended body, each part often applies forces on the adjacent parts; the distribution of such forces through the body is the internal mechanical stress. In equilibrium these stresses cause no acceleration of the body as the forces balance one another. If these are not in equilibrium they can cause deformation of solid materials, or flow in fluids. In modern physics, which includes relativity and quantum mechanics, the laws governing motion are revised to rely on fundamental interactions as the ultimate origin of force. However, the understanding of force provided by classical mechanics is useful for practical purposes.[1] Development of the concept Pre-Newtonian concepts Newtonian mechanics Combining forces Examples of forces in classical mechanics Concepts derived from force Units Revisions of the force concept Fundamental interactions See also References External links Last edited 18 days ago by HansVonStuttgart Wikipedia Content is available under CC BY-SA 4.0 unless otherwise noted. Privacy policy Terms of UseDesktop Encyclopedia Britannica HomeGames & QuizzesHistory & SocietyScience & TechBiographiesAnimals & NatureGeography & TravelArts & CultureMoneyVideos Home Science Physics Matter & Energy Science & Tech force physics Written and fact-checked by Article History Force, in mechanics, any action that tends to maintain or alter the motion of a body or to distort it.

1. Forces

16. Force and Net Force
•Force is a push or
a pull on an object.
•Net force is the
total force on an
object.

17. Unbalanced Force
Balanced Force
• Unbalanced Force
can cause an
object to move,
stop moving, or
change direction.
•The balanced
forces are the
forces in equal
and opposite
directions.

19. Forces change
motion.

20. •

21. Inertia
–An object at rest
will stay at rest
unless acted upon by
an outside force.
–Inertia is every
objects resistance
to change its
motion.
Newton’s First Law
Greater mass
means
Greater inertia

23. Newton’s Second
Law
• The acceleration of an object is
directly proportional to the net force
acting on the object and inversely
proportional to the object’s mass.

24. Force=mass x acceleration
F=m x a
•Or
•a = Force/ mass
•a = F/m

25. Equation for Newton
•Newton=m x a.
It’s the same
as the force
equation!

26. Force and mass
determine
acceleration.

27. Sometimes we might calculate
mass using Force and
Acceleration
• Mass=Force/Acceleration
• m=F/a

28. How much Force was required to
make a 2000kg car accelerate at
5m/s?
1. 400N
2. 0.001N
3. 10,000N

30. If you drop a 15kg bowling ball
with a Force of 147N, what is it’s
acceleration?
1. 9.8m/s/s
2. 0.1m/s/s
3. 2,205m/s/s

32. A person throws a baseball at an
acceleration of 25m/s/s with
12.5N of Force. What’s the Mass
of the ball?
1. 312kg
2. .5kg
3. 2kg

34. 4 Types of Friction
• The 4 types of friction are:
1. Sliding friction (strongest)
2. Rolling friction
3. Fluid friction (weakest).
4. Static friction

35. • What
type of
friction?

36. •What
type of
friction?

37. •What
type of
friction?

38. What type of friction?

39. 2 Factors of Friction
• 1-Type of surface.
• 2-How hard the two
surfaces push together.

40. •
Which type of hockey has
more friction?

42. Air Resistance
and Weight
•Air resistance is a type
of fluid friction on falling
objects. Weight is the
force of gravity on an
object at the surface of
the Earth.

44. Law of Universal
Gravitation
• Gravity acts between all
objects in the universe.

45. Gravity Between Objects
• The force of gravity between objects
increases with greater mass and decreases
with greater distance.

47. •

48. • Gravity is the
force that pulls
objects toward the
Earth-
acceleration due
to gravity is
9.8m/s/s.

50. Newton’s Third law
• If an object exerts a force
on another object, the
second object, exerts an
equal force in the
opposite direction.

55. Momentum
• The momentum of an object
is the product of its mass and
velocity.
• In other words:
Momentum = mass x velocity
• Kg x m/s

56. COLLISIONS

58. Law of Conservation of
Momentum
• The total momentum of
the objects that interact
does not change.